This perspective is classically biased, I'm afraid to say. :/ I agree with you (now, given other's comments) that it may not be an appropriate conversation to ask LW to host.... but if you write off the possibility of its veracity as "fantasy" before studying the material, you are exhibiting a preconceived notion independent of the data. It's like when Einstein wrote off quantum mechanics as "too weird".
The universe acts just as we would expect a mechanistic, material universe to act. I have seen the argument you made in other comment threads, and I find it too weak to be worth much consideration. You suggest that God exists (along with heaven, souls, etc.). The only direct impact those entities seem to have on the universe, though, is the presence of a few vaguely-stated tidbits in a book that can be charitably interpreted to have been uncommon knowledge at the time they were written down. Notably, they were written down in connection to previous books which contain vast historical and factual inaccuracies and are better understood as mythology rather than revelation. This simply is not very convincing.
In this comment thread, I gave the following idea, on the topic of a method by which one might judge the Book of Mormon from a rationalist perspective:
I would appreciate feedback on this idea, for an admittedly selfish reason: I am trying to instigate in myself a Crisis of Faith. So, here are the questions I pose to you: